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• What is CERN? • General overview of CERN • What is LHC? • The LHC accelerator and LHC challenges • Student projects at CERN • Range of subjects, examples of NTNU Master’s thesis at CERN • Working at CERN • Professional environment, life in the Geneva region Jens VIGEN, CERN/ DSU Nils HØIMYR CERN / IT CERN – for HIG students

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What is CERN? The special tools for particle physics are: • ACCELERATORS, huge machines able to speed up particles to very high energies before colliding them into other particles • DETECTORS, massive instruments which register the particles produced when the accelerated particles collide

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• Physicists smash particles into each other to: - identify their components - create new particles - reveal the nature of the interactions between them - create an environment similar to the one present at the origin of our Universe • What for? To answer fundamental questions like: how did the Universe begin? What is the origin of mass? What is the nature of antimatter? What is CERN?

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The World Wide Web was invented here, to improve and speed-up the information sharing between physicists working all over the world! What is CERN?

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• CERN has made many important discoveries, but our current understanding of the Universe is still incomplete! • Higher energy collisions are the key to further discoveries of more massive particles (E=mc 2 ) • One particle predicted by theorists remains elusive: the Higgs boson What is CERN?

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• To answer questions still open, CERN is building the Large Hadron Collider (LHC) • The LHC will be the most powerful instrument ever built to investigate elementary particles • If the Higgs boson exists, the LHC will almost certainly find it What is CERN?

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• LHC will collide beams of protons at an energy of 14 TeV • Using the latest super-conducting technologies, it will operate at 1.9K (about –271 0 C), just above absolute zero of temperature. • With its 27 km circumference, the accelerator will be the largest superconducting installation in the world. What is LHC? LHC is due to switch on in 2007 Four experiments, with detectors as ‘big as cathedrals’: ALICE ATLAS CMS LHCb

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• A particle collision = an event • Physicist's goal is to count, trace and characterize all the particles produced and fully reconstruct the process. • Among all tracks, the presence of “special shapes” is the sign for the occurrence of interesting interactions. One way to find the Higgs boson: look for characteristic decay pattern producing 4 muons The LHC Data Challenge

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Computing for LHC • Problem: CERN alone can provide only a fraction of the necessary computing resources • Solution: Bring the LHC data to the users! Computing centers, which were isolated in the past, should now be connected, uniting the computing resources of particle physicists in the world! Europe: 267 institutes 4603 users Elsewhere: 208 institutes 1632 users

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What is the Grid? • The World Wide Web provides seamless access to information that is stored in many millions of different geographical locations • In contrast, the Grid is an emerging infrastructure that provides seamless access to computing power and data storage capacity distributed over the globe. •Aka: Power Grid, distributed computing, metacomputing